Floating transfer bridge



Dec. 25, 1962 J. B. WARD FLOATING TRANSFER BRIDGE 3 Sheets-Sheet 1 Filed Dec. 5, 1960 IN VEN TOR.

JOSEPH B. WARD Dec. 25, 1962 J. B. WARD FLOATING TRANSFER BRIDGE 3 Sheets-Sheet 2 Filed Dec. 5, 1960 Dec. 25, 1962 W 3,069,862

FLOATING TRANSFER BRIDGE Filed Dec. 5, 1960 3 Sheets-Sheet 3 czzkm J- s C 2 l Ng I TD g o E 3 Q i a 8 8 INVENTOR. JOSEPH B. WARD" BY M 3,059,862 Patented Dec. 25, l62

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3,069,862 FLOATING TRANSFER BRIDGE Joseph B. Ward, 869 (Ientral Bldg, Seattle 4, Wash. Filed pee. 5, 1960, Ser. No. 73,862 5 Claims. (Cl. 61-48) This present invention relates to transfer bridge construction wherein one end of the bridge is pivotably secured on the shore end and pivotably mounted upon a floating pontoon at its seaward end. More specifically, this invention relates to transfer means for loading and unloading wheeled vehicles from a floating car-barge, ferry, train-ship, or other floating vessel. Means are further provided so that the transfer means will provide a suitable passageway from the vessel to shore which may be adjusted to compensate for tidal action or varying levels of the vessel as it is being loaded or unloaded.

There is an increasing demand for the transfer of loaded vehicles from one port to another. In the larger ports this transfer problem is met by permanent installations of suitable dockage and mechanical adjusting means so that wheeled vehicles of various types, including railroad cars, may be loaded aboard ship at any time without undue difficulty. In the outlying small ports, however, such as are common along the undeveloped coast of British Columbia and Alaska and other like areas throughout the world the problem of loading and unloading loaded wheeled vehicles presents a very difficult problem. Particularly for railroad cars the transfer is a very difficult one due to the fact that the cars themselves as well as their loads are heavy and the grades up which they can be handled is usually only a fraction of that which can be negotiated by motor vehicles. In the small ports it is necessary to have means that will compensate, first, for change in level between the shore end of the railroad and the deck of the boat as it is affected by tidal conditions and, secondly, for the changing buoyancy of the vessel in loading or unloading. My present equipment is believed to provide a very acceptable solution of this problem permitting rapid loading or un- 4 loading of a vessel and providing this at a reasonable cost, thus keeping the whole venture within economic bounds.

A principal object of this present invention, therefore is to provide a transfer bridge, one end of which is floating, and to maintain the floating end at substantially a constant level with respect to the water level to facilitate the loading or unloading to or from the deck of a barge or other floating vessel.

A further object of this invention is to provide a trans- U fer bridge in which its shore end is pivotably secured for movement in a vertical plane and which has its seaward end supported by a pontoon float which raises and lowers the seaward end of the bridge section as the tides change the water level.

A further object of this invention is to provide additional pivoted means, pivoted to the main bridge at one end and supported from the pontoon at its other end to maintain the seaward end of the combined transfer bridge at a suitable unloading level with respect to the deck of a barge or other floating vessel.

A further object of this invention is to provide a pen toon float for the seaward end of a transfer bridge, the level of which can be adjusted to a required level by water ballast means.

A further object of this invention is to provide power operated lift means which will maintain a precise relationship between the seaward end of the transfer bridge and a barge or deck of a ship as the floating vessel changes trim due to the shifting of weight by the loading and unloading of the wheeled vehicles.

A further object of this invention is to provide, preferably, only a single set of rail tracks but one which can be adjusted accurately and quickly to unload or load from any one of a plurality of rail car tracks on the floating vessel.

Further objects, advantages and capabilities will be apparent from the description and disclosure in the drawings or may be comprehended or are inherent in the device.

FIGURE 1 is a top plan view showing my transfer bridge and the pontoon which provides buoyancy for the outer or seaward end of the bridge section, illustrating the two extreme positions of a barge having a plurality of rail tracks and showing how it can be conveniently aligned with the track of the transfer bridge.

FIGURE 2 is a side elevation of the structure of FIG- URE 1.

FIGURE 3 is an enlarged view of a portion of FIG- URE 2 showing in greater detail the structure employed at the seaward end of the bridge section and the pontoon means used to give it buoyancy.

FIGURE 4 is an enlarged top plan view showing a barge and the seaward end of my unloading transfer bridge and illustrating a modified form thereof.

FIGURE 5 is a top plan view illustrating a form of barge maneuvering means used with my equipment and showing the seaward end of my transfer bridge member in fragmentary form.

FIGURE 6 is a vertical diagrammatic view showing the means for moving and securing a barge in its adjusted transverse position.

FIGURE 7 is a fragmentary view in elevation illustrating the location of the position sensing and electrical switching devices.

FIGURE 8 is a face view of one of the sensing and switching devices.

Referring to the drawings, throughout which like reference characters indicate like parts, 1t) designates the bridge section. This unit is preferably for-med of prestressed concrete which is cellular in form and is provided with an upper closured web or deck 12 and a lower closure web or bottom 14. The deck and bottom are concrete slabs which make the bridge section floatable. The enclosing slabs are of suflicient thickness to give strength intermediate the transverse ribs 16 and the longitudinal partition ribs 13. It is not intended that the bridge section will be buoyant because of this compartmentation while actually in use. However, the compartmentation does give a very strong lightweight concrete structure making it possible to construct the bridge section in relatively long lengths and to then float the same into position where it can be easily secured to the shore by pivots 2%. Normally, a plurality of pivots 20 are employed which are axially aligned and properly supported as by piers 22. These pivots are to take care of the vertical movement of the bridge section but, because of the length of the bridge section and the fact that it is normally subject to wave action, additional means must be provided to insure working positioning of the bridge section. This is usually provided by a plurality of piling as at 24 and 26 which is usually bound together to form a dolphin of sufficient strength to resist any wave or current action in moving the bridge section transversely but which will still give a slight degree of resiliency. To this end pivots 20 should be arranged to accept this limited movement of the bridge section.

At its seaward end bridge section 10 is pivotably secured at 3% to a compartmentized pontoon float 32. Normally a plurality of pivots 30 are used in axial alignment transversely of the bridge section and these should be disposed equally with respect to the center of buoyancy of pontoon 32 so there will be no tendency on the part of the pontoon to overturn in either direction. Normally pivots 20, on the shore end of the bridge section, are selected at an elevation most suitable for connection to the rail tracks 34 and once installed the bridge section is permanently anchored at pivots 20. The purpose of the pontoon is to raise or lower the seaward end of the bridge section in order to compensate for tidal diflierenee in elevation of the water surface. It is to be understood that several factors aifect the level of the tracks on the transfer bridge as well as on the ship being served, namely, the normal level of the deck of the various seaborne vessels to be accommodated, the displacement of the vessel due to its loading, and finally the varying differences in level of the deck as the vessel is loading or being unloaded.

In order that the trackage on the bridge section will be substantially at the same elevation as that of the vessel, it has been found necessary to employ a plurality of valves or seacocks 38, which are normally provided with motorized control means, usually on about the level of the trackage. Seacocks should be provided for all the various compartments so that they can control the vertical height of the pivot point 30 and also can be employed to change the trim of the pontoon itself to maintain it in a substantially level floating condition at all times. In normal use the opening of the seacocks allows water to flow into the pontoon compartments 40 and lower the pontoon. To make it possible to raise the pontoon, a plurality of discharge pumps 42 are provided, preferably, one for each separate compartment which normally should have about the same water handling capacity as the seacocks in order that the changes of elevation can be made within the time limits indicated as desirable.

Pontoon 32 is positioned by two agencies. The bridge section 10, through the pivoted connections at 30 determines the distance of the pontoon from pivots 20. The transverse positioning is assured by the pile dolphins 24 and 26 which first, definitely position the pontoon and then insure that the bridge section will not swing in a horizontal plane about pivots 20 in excess of the amount that can be properly taken care of by the mounting of pivots 20.

Experience has shown that the pontoon, which normally has considerable mass and depth, will not be as quickly responsive to the flotation effect of the water as are the various types of floating vessels. Because of this fact, it has been found that the water ingress and egress means for the pontoon must handle a considerable amount of water in order to change the vertical height of the pontoon. Further, it is difiicult to make changes in the level of the pontoon fast enough to take care of the relative vertical movement of the pontoon and the vessel. It has therefore been found desirable to employ an equalizing jumper section 50 which is pivotably secured at 52 to the bridge section at one end which forms a continuation of the bridge section deck 12, including the rail tracks as well as lateral extensions 54 and 55. These lateral extensions are desirable as a maneuvering space for the necessary handling equipment and the essential personnel employed to operate the same.'

The jumper section is preferably also formed of prestressed concrete construction and will therefore have considerable mass. The length of the jumper section along the axis of the bridge section 10 should be considerable and the design characteristics covering its length will be the expected elevation range of the seaward end 56 which must move in accordance with the difference of the movements between the pontoon and the vessel being served.

A second consideration is the frequency with which the changes in level must be effected. It follows that to make a joining of rail tracks on the jumper and those on the deck of the vessel an elevating means must be provided which is quick in operation as distinct from the buoyancy control of the pontoon, and for this purpose power operated positioning means which are preferably under the surface of the deck are employed. These may be hydraulic jacks 53 or mechanically operated means which must, in any event, be quickly responsive to an operators manual operation, or to an operation that is preferably triggered by sensing means disposed to register the difference in level between the jumper section trackage and the trackage of the vessel being served.

A suitable sensing and electrical switching device is illustrated in FIGURE 8. A base 56 is pivoted at 57 and yieldably positioned by springs 56a and 5612. A probe 59 is pivoted to base 56 and confined to a limited transverse movement by stops 59a and 5912. Spring 61 biases the probe away from the micro-switch 63. The electrical current controlled by the switch is preferably lead to a relay, not shown, to operate a reversible motor suitably arranged to move the barge transversely with respect to jumper 50 or to move the jumper vertically with respect to the barge B. Normally a minimum of four of the sensing devices are required and a minimum of two electric motors. This mechanism only supplements the hydraulic positioning of pontoon 32. It is quickly responsive while the pontoon is necessarily slow in its movements as pointed out previously.

Reference is now made to the plan view made in FIG- URES l, 4 and 5, where it will be noted that the top deck 58 of jumper section 54} has its seaward end beveled off both ways from the track axis as is indicated at 60 and 62. These beveled portions join a short central face portion 64 which is normal to the longitudinal axis of the rail tracks. Any of the various types of vessels which will be employed to transport rail cars must, as an economic consideration, carry a plurality of tracks so that the carrier can be adequately loaded and balanced for its water borne trip. It has been found that the structure of this transfer bridge becomes large, heavy and somewhat costly even when a single set of tracks 66 is employed. It is therefore not practical to employ a plurality of tracks which would involve transverse balancing, enlarged pontoons, and many other considerations, all of which would increase bulk as well as cost of the transfer bridge structure. It therefore has been found that as the carrier is maneuvered from the three pile dolphins, 70, 72, and 74, that the unloading end of the barge or other carrier can be brought into unloading position with respect to track 66 by the maneuvers indicated in FIGURES l, 4 and 5, wherein suitably arranged cable portions 76 and 77 can be operated to move the barge B so as to effect the operational alignment. Suitable manipulation of cable portions 76 and 77 by an operator normally mounted on one of the platforms 54 or 55, will make it possible to quickly move barge B, or any other type vessel being served, the relatively small amount necessary to bring the desired trackage of the vessel in operational alignment with the single track 66 and its continuation on the equalizing jumper section 50.

The transverse maneuvering of the shore end of barge B is probably best shown in FIGURES 4, 5, 6 and 7. A satisfactory arrangement is to provide, in effect, an endless cable 75 having the securing portions 76 and 77. Loops 78 and 79 formed by cable clamps are provided to engage the bits 86 and 82 positioned on opposite sides of barge B. A bight of cable 84 connects the loops and insures the convenient positioning of the loops when barges B are being changed. The cable is reeved through sheaves as and 87 to form the under-water bight 88. Powered Winches are provided at 90 and 91 with a powered take-up winch at 93 to which both ends of the cable are normally secured. The motors of winches 9th and 91 are responsive to the sensing and switching of switch means 56 disposed to sense transverse movements.

It is believed that it will be clearly apparent from the above description and the disclosure in the drawings that the invention comprehends a novel construction of transfer bridge for transferring wheeled vehicles.

Having thus disclosed my invention,

1 claim:

1. A transfer bridge for unloading and loading wheeled vehicles from a floating train-ship or other floating vessel having a plurality of longitudinal rail tracks, comprising, a longitudinally tracked transfer bridge section pivotally secured at its land end for pivotal movement thereof in a vertical plane, a floating pontoon having pivot means disposed at the axis of buoyancy thereof, said pivot means pivotally supporting the floating end of said transfer bridge section, a jumper bridge pivotally supported at its shoreward end by said transfer bridge section, means carried by the seaward end of said pontoon for supporting the seaward end of said jumper bridge in a vertically adjustable manner, an equalizing section of trackage mounted on said jumper bridge and disposed to coact with the trackage of said transfer bridge section, and vertical guide means of piling driven into the sea bottom and positioned to slidingly engage said jumper bridge section to confine the same against lateral movement.

2. The subject matter of claim 1 in which the seaward end of said jumper bridge is beveled in the horizontal plane, shoreward on each side from the axially positioned trackage, to adapt it for engagement with the end of a water craft.

3. The subject matter of claim 1 in which water ballast means is provided for said pontoon; said means '67 including valve means disposed to admit water to said pontoon and Water rejection means to discharge water from said pontoon to change its floatation level and thus compensate for the changing level of the water craft as it is loaded or unloaded.

4. The subject matter of claim 1 in which said transfer bridge section is of cellular form to provide floatation for said bridge section so the same may be transported by towing to the point of installation.

5. The subject matter of claim 1 in which the seaward end of said jumper bridge is positioned vertically and horizontally by motor driven means controlled by sensing means actuated by the relative movement of said jumper bridge and the floating vessel being serviced.

References Cited in the file of this patent UNITED STATES PATENTS 1,778,667 French Oct. 14, 1930 2,200,550 Helmers May 14, 1940 2,381,789 Turnbull Aug. 17, 1945 2,714,735 Watson Aug. 9, 1955 2,768,599 Harris Oct. 30, 1956 2,857,872 Usab Oct. 28, 1958 FOREIGN PATENTS 529,888 Germany July 18, 1931 1,028,499 Germany Apr. 17, 1958 

